1. Field of the Invention
The present invention relates to an apparatus for forming a developed image onto a recording material of a device, such as a copying machine or printer.
2. Description of the Related Art
Various electrical equipment units must be used in order to drive image forming apparatuses. For example, typical electrical units are: an engine unit for controlling components such as a power supply, a paper feed unit, a scanner and a fixing unit, and an image controller for converting image codes transmitted from a host computer into dot images. The image controller is composed of highly integrated components, such as a microprocessor. Accordingly, in many cases, multilayered and double-sided substrates are employed to make effective use of space and reduce radiation noise. The engine unit is composed of large and heavy components, such as the power supply and a transformer. The degree of integration of these components is lower than that of the components of the image controller. Therefore, single-sided substrates are employed for the engine unit. The cost of single-sided substrates is lower than that of multilayered and double-sided substrates. The single-sided substrates are sufficient for use in the engine unit.
For these reasons, it is preferable that the engine unit and image controller be separately attached to an image forming apparatus. It is also preferable that the engine unit be covered with "grounded sheet metal" because the engine unit produces relatively high magnitude radiation noise.
Nonetheless, radiation noise is transmitted to the image controller through a connector which connects the engine unit to the image controller and then it is transmitted from the image controller to the outside. The image controller, like the engine unit, may be covered with "grounded sheet metal". However, it is not desirable to cover the image controller with "grounded sheet metal", since to do so would increase the cost of the image forming apparatus and make it difficult to replace one image controller with another one in accordance with the type of external computer being used.
Thus, the radiation noise transmitted from the image controller causes a problem.
In conventional image forming apparatuses a paper feed roller, a carrier roller, image forming means, such as a photosensitive drum, a developing roller and a charge roller, and other components are operated by force from a driving source through driving force transmitting device. A plurality of drive gears are usually used as the driving force transmitting device. As shown in FIG. 3, the drive gears are arranged on both sides of the image forming apparatus, as viewed from the direction indicated by arrow A. These gears are rotatably supported by a plurality of supporting members, and thus they occupy large portions within the apparatus.
Accordingly, the foregoing conventional image forming apparatus suffers from the above-described problems of radiation noise transmitted from the image controller and bulky arrangement of the drive gears.